A conventional induction heating cooking apparatus is disclosed in, for example, Japanese Patent Unexamined Publication No. H9-312195. FIG. 12 shows the structure between a heating coil and an inverter board in a conventional induction heating cooking apparatus. Top plate 1 for placing a cook pot, etc thereon is made of a ceramic plate or the like material. Disposed underneath top plate 1 is coil 2 for generating a line of magnetic force for induction-heating a cook pot. Coil 2 is mounted fixed on supporting bed 3. Inverter board 4 for supplying high frequency current to drive coil 2 is disposed underneath supporting bed 3. Inverter board 4 is held on board holder 5.
Board holder 5 is provided with a plurality of support bosses 6 for holding supporting bed 3. Elastic body 7 composed of a coil spring is provided at support boss 6, with the boss' column formed at the center inserted in the coil spring. Holding section 8 is integrally formed at the outer circumference of supporting bed 3. It has a cylindrical shape with one end open towards down, and disposed to cover the upper end of elastic body 7. Supporting bed 3 is held by these parts. Supporting bed 3 is further provided with a plurality of push-up bosses 9 located on holding section 8. Push-up boss 9 is pushed upward by elastic body 7 until it reaches the reverse surface of top plate 1. This structure keeps the gap between coil 2 and top plate 1 constant. The up-down sliding distance A of supporting bed 3 is dependent on the shape and the spring force of elastic body 7. The distance A is required never to be smaller than the minimum value of a gap B between bottom plane 10 of the supporting bed and top surface 11 of the electronic components.
When a cooking apparatus of the above-described conventional structure in the packaged state is dropped by mistake, the apparatus itself is hit by an impact force. Here, supporting bed 3 which supports coil 2 is held by elastic body 7. Thus, the elastic body is compressed downward allowing the supporting bed 3 to slide down. In such an occasion, supporting bed 3 is pushed down until it makes contact with top surface 11 of electronic components mounted on inverter board 4. Thus the electronic components undergo a stress, and inverter board 4 may also be damaged together with the components.
In order to protect the electronic components from the stress, the minimum value of the gap B between bottom plane 10 of the supporting bed and top surface 11 of the electronic components is made large, or the spring force of elastic body 7 is made stronger in the conventional structure. When the minimum value of the gap B is increased, the electronic components can not be mounted at high density within a space in the apparatus, which results in a greater overall height with finished apparatus. This is unacceptable in view of the prevailing product trends for the smaller and the slimmer design. On the other hand, when the spring force of elastic body 7 is increased by modifying the material or the shape of elastic body 7, the impact force to be given to top plate 1 by push-boss 9 increases. This means a greater possibility of damage on top plate 1 because of greater impact to top plate 1 when the apparatus in the packaged state is dropped.